Roll suction device



Jan. 26,1932. M; WE ZEL. 1,842,924

ROLL SUCTION DEVICE Filed Dec. 1930 Patented Jan. 26, 1932 PATENT OFFICE MAX WENZEL, OF MULDENSTEIK', NEAR BITTER-FIELD, GERMANY ROLL SUCTION DEVICE Applicationfiled December 8, 1930, Serial No. 500,774, and in Germany December 16, 1929.

5 Among the several objects of the invention may be noted the-provision of a device of the class described in which a suction box is divided into separate compartments for air and for water; the provision of a device of the class described in which there is provided a separate trough 01' sump placed within a suction box; the provision of a device of the class described in which there is provided means for relieving the said trough orsump of air pressure, thereby permitting it to be more economically made, even though it be composed of a non-corroding and therefore more expensive materials; the provision of a device of the class described in which there is provided means which reduces the formation of injurious deposits of paper pulp and the like; and the provision of a device of this class which is simple, effective, and which finds a wide application in different sizes and types of apparatus. Other objects will be in part obvious and in hereinafter.

The invention accordingly comprises the elements and combinations of elements, features of construction, and arrangements of parts which will be exemplified in the structure hereinafter described, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings, in which are illustrated several of various possible embodiments of the invention, I

Fig. 1 is a diagrammatic, longitudinal section of a suction box and roller;

Fig. 2 is a cross section showing successive suction boxes and rollers, the section at the left of the figure being taken in plane A-A of Fig. 1 and the section at the right being taken in plane BB of Fig. 1;

Fig. 3 is a longitudinal section corresponding to Fig. 1 and showing a second embodiment of the invention; and, i

Fig. 4 is a view similar to Fig. 2 showing the second embodiment of the invention, the

part pointed out left and right sections being taken on lines CC and DD of Fig. 3, respectively.

Similar reference character indicate corresponding parts throughout the several views of the drawings.

Referring now to the drawings, and more particularly to the embodiment illustrated in Figs. 1 and 2, there is represented at numeral 1 a screen or sieve on which a wet web of paper pulp is disposed and from which water is to be removed. A number of rollers 3 carry screen 1 and are transversely mounted therebeneath. Below the rollers 3 there is provided a series of suction boxes 5 provided with longitudinal packing ledges 7, said ledges forming a substantially air-tight, Water seal between the rotating rollers3 and the box 5;

Within the suction boxes'5 and between and along the ledges 7, sumps or-chutes or troughs 9 are disposed. These chutes 9 may conveniently be supported between the upper edges of the suction boxes 5 and the lower edges of the packing ledges 7, and are preferably made of some non-ferrous, non-corrosive material such as brass, copper, or the like. The troughs are preferably shaped'so as to have smooth lateral walls as steep as possible and a rounded bottom portion.

It will be noted that the bottoms of these troughs 9 are held in a longitudinal and inclined position with respect to the suction boxes 5 and the rollers 3, and terminate at their lowermost portions in discharge suction tubes 11 which are placed at one end of the suction boxes 5. At the other end of the suction boxes there are provided a second set of discharge suction tubes 13. The bottoms of the troughs 9 are therefore each inclined from above tube 13 towards tube 11 with the upper edges of the troughs fastened to the horizontal top edges of the suction boxes 5. The troughs 9 therefore divide the suction boxes 5 into two compartments 15 and 17. The upper compartments 15 are defined by the troughs themselves; the lower compartments 17 aredefined by the walls of the boxes 5 and the troughs 9.

The discharge suction tubes 11 are connected to a pump or other device so as to produce a partial vacuum within the compartments 15. Inasmuch as this vacuum also extends throughout the volumes defined by the packing ledges 7 and rollers 3 (see Fig. 2) itis clear that there is an air pressure acting downwardly on the wet mat of paper pulp on screen 1. This pressure forces water in the wet mat down through the screen 1 into troughs 9 and it is discharged through the tubes 11.

The suction water 19 passing through the screen 1 incidentally carries with it some of the paper pulp and is sometimes called white water. Inasmuch as the bottoms of troughs 9 are mounted in an inclined position and are rounded there is little or no opportunity for quantities of the pulp to settle out of the white water and collect within the troughs.

The suction water is afforded a constant and V smooth flow with little opportunity to form eddy currents which would produce deposits of the paper pulp as may be formed where an ordinary suction box is used.

In addition to the white water which comes through the screen 1 there is also some air sucked through. For the purpose of discharging this air, there are provided the suction tubes 13 and by-pass openings 21 in the sides of the troughs 9. These openings 21 are above the level of the water 19 and bypass the suction air from chamber 15 into chamber 17. A suction is created in chamber 17 by communication with the suction tube 13. The suction air entering chamber 15 along with the suction water 19 is therefore free to pass from chamber 15, through the openings 21, into chamber 17, and out through the discharge tube 13, as shown by the arrows. Thus it is seen that the tube 11 discharges the white water and the tube 13 discharges air.

To prevent quantities of the white water which follow the packing ledges 7, or drippings from the rollers 3 or screen 1, from being carried along with the discharge air, the portions of the walls of the troughs 9 which are located beneath the openings 21 are bent outwardly towards the walls of the suction boxes 5, as shown at numeral 23 (Fig. 2), thus providing a shingle effect. The same result obtains if the wall portions are bent as shown at numeral 25 (Fig. 2).

The troughs 9 are substantially relieved of air pressure and are subjected to only th' weight of the water 19. This condition exists because the chambers 15 and 17, which are separated by the troughs 9, are both suction chambers. The troughs 9 may therefore be more economically made. A further economy arises in that the design of the troughs 9 is independent of the material and shape of suction boxes 5. The suction boxes 5 may be made of iron or some material cheaper than thetroughs 9. Inasmuch as the suction walems of corrosion and the like of the boxes 5 are practically eliminated, and the noncorroding sump or trough which is made of more valuable materials may be made lighter, because it is not subjected to a substantial pressure diiferential within and without.

In the embodiment shown in Figs. 3 and 4, the same reference numerals as are used in Figs. 1 and 2 are used to designate parts performing the same functions as the parts of Figs. 1 and 2.

Several differences in the structures of the two embodiments exist. Instead of the discharge tubes 11 and 13 leaving the suction to boxes 5 perpendicular to the rollers 3, these tubes are parallel to the rollers. Also the suction boxes 5 are round instead of square or rectangular, and the packing ledges 7 are closer together and are juxtaposed with respect to a pair of rollers 3 instead of including therebetween a. roller 3 as shown in Fig. 2. Instead of longitudinal openings 21 in the sides of the troughs 9, there are provided series of openings 26.

It will be noted that the positioning of the packing ledges 7 as shown in Fig. 4 produces a suction which is effective over a. width 7); whereas Fig. 2 shows a positioning which produces a suction effective over a width 0. Both widths are shown to illustrate the flexibility of design that is possible when using this invention.

It is to be understood that the suction for all the suction boxes and that the areas over which the suctions of the boxes are effective are not necessarily the same. Furthermore, the method of supporting the screen 1, may be varied. For example, the rollers 3 and the packing ledges 7 may be dispensed with, in which case the upper edges of the suction boxes 5 would be adjacent the screen 1. Furthermore, the openings 21 (Figs. 1 and 2) and 26 (Figs. 3 and 4) may be of many different shapes and may be distributed over the entire length or a portion only of the troughs 9.

It is also to be understood that the pipes 11 and 13 may join and deliver air and water to a common receptacle. Also, the suction may or may not be on the water discharge line. The discharge line may act as a plain drain or as a. suction liquid line.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As many changes eouldbe made in carrying out the above constructions without departing from the scope Jr the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. In a device of the class described, a suction box, a discharge tube, and a trough, said trough being mounted within said box and being inclined towards and leading into said discharge tube.

2. In a device of the class described, a suction box,a discharge tube, and a trough, said 8 trough being mounted within said box and being formed so as to leadsuction water to said discharge tube.

3. In a device of the class described, a suction box, a discharge tube, and a trough, said trough being mounted within said box and packmg' ledges, said packin ledges being adapted to engage said troug so as to, keep suction water from entering said box.

4. In a device of the class described, a suction box, a discharge tube, a trough within said box, and means for equalizin air pressure on said trough, said trough being adapt-' ed to deliver suction water to said tube.

5. In a device of the class described, a sucin said box-so as to divide said box into' two compartments, a discharge tube commumcating with one of said compartments forearrylng away suction water, and a second discharge suction tube communicating with said second compartment for carrying away suctiona'ir.

6. In a device of the class described, a suction box, a trough, said trough being mounted in said box so as to divide said box into two compartments, a discharge tube communicating with one of said compartments for carrying away suction water, and'a second discharge suction tube communicating with said second compartment, said trough having at least one opening communicating between said compartments, said second suction tube being adapted to discharge suction air from said first compartment by sucking said air '9 through said opening into said secondcom partment. V

7. In a device of the class described, a suction box, a trough, said trough being mounted within said box so as to divide said box into. an upper and a lower compartment, a discharge tube, said trough delivering suction water to said tube, air suction means, and means for relieving saidtrough of substantial differential air pressure.

8. In a device of the class ,described, .a

suction box, a trough, said trough being tion box, a trough, said trough being mounted ledges and said box so to'exclude suction water from said box.

10. A roller suction device for ma-- chines comprising rollers, a screen carried by sald rollers, a suctlon box beneath said rollers, a packing ledge adapted to seal said rollers and said box and a trough-within said box, said trough being adapted to receive and discharge suction water coming from the material carried by said screen.

11. A roller suction device-for paper machinescomprising rollers, a screen carried by said rollers, a suction box beneath said, rollers,'a packing ledge adapted to seal said rollers and said box, a trough -within said box and means for substantially equalizing pressure on said trough. v r

12. A roller suction device for paper machines comprising rollers, a screen carried by said rollers, a suction box beneath said rollers, a packing ledge adapted toseal said rollers and said; box, a trough within said \box, a discharges tube for carrying suction water away from 'saidtrough, and means for substantially equalizing pressure on said trough, said means comprising a suction pipe communicating with said box. 1

. 13. A roller suction device for paper machines comp rising rollers, a screen carried by said rollers, a suction box beneath said rollers, a packing ledge adapted to seal said rollers and said box; a trough within said box, said trough being mounted within said box so as t0-divide said box into two compartments,,adischarge tube for suction water communicating with one of said compart ments andsaid ti'ough,'and a discharge tube for suction air, said second discharge tube communicating with said second compartment.

In testimony whereof, I havesigned'iny name to this specification'this 25th day of November, 1930.-

- MAX WENZEL.

V mounted within said box'so as to divide said compartment, and means for relieving said trough of air pressure.

9. A roller suction device for paper machines comprising rollers, a screen carried by said rollers, a suction box beneath said rollers, a packing ledge adapted to seal said rollers said trough being supported betweensaid and said box and a trough within said box,. 

